Diaphragm for sound-reproducers.



P. W. THOMAS.

. DIAPHRAGM FOR SOUND REPRODUGERS.

WITNESSES APPLICATION FILED 111111.11, 1913.

Patented Nov. 3. 1914. I

ATTORNEYS FREDLERZC THOMAS, 0F NEE CITY, NEW

DIAPHRAGM Iiitllt SOUBlD-REERGDUCERS.

.ipplicstion 35ers 11. 1813. Eel-i111 No. '!53,78.

Specification of Letters retest.

.L "1.7: i 13a centers New To all whom. it m a-g 0021mm:

Be it known that I, FREDERIC W. THOMAS, a citizen oi? the Unit-sci States, and a resident of New City, in the county of Roclzlsncl and State of New York, have invented a new and Improved Diaphragm for Souncl-Repreducers, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and. improved diaphragm for sound reprooluoers such as are used in gramophones, graphophones, receivers and. tran mitters of telephones and other sounei-reproducing instruments and machines and which is exceedingly sensitive for the reproduction of sounel vibrations.

In order to accomplish the desired result use is made of a diaphragm of metal made exceedingly dense or compact throughout bv pounding, beating, pressing, hammering or similar processes.

A practical emhoclinient of the invention is represented in the accompanying draw ings forming apart of this specificstion, in which s milar characters of reference incli? cate corresponding parts in all the views.

Figure 1 is a face View of the diaphragm as applied to a. graphophone sound box shown in clotted lines; Fig. 2 is an enlarged cross section of the diaphragm on the line 2-2 of Fig. 1, and showing in dotted lines the ring for compacting the perip eral edge of the diaphragm; and Figs. 3 and 4 are cross sections of diephragins of difi'erent shapes.

The diaphragm A is made of suitable metal, and its texture is rendered exceeciingly dense or compact throughout by pounding, beating,pressing, hammering or similar processes, wherein the pressure is applied perpendicularly or normally to the plane or final surface of the diaphragm. In practice, according to one method a blank, preferably of disk shape, is out from a piece of sheet metal and this disk is then subjected to a pressure other than rolling,

as pounding, beating, pressing, hamineing or similar action to stiffen the disk and to render it very dense or compact by closing up the pores and expelling the air therefrom. According to another methorl the sheet of metal of which the @iaphragms are to he made may he treated in sheet form in the manner just (lescribeel, and the disks then cut out to proper size and form. It is expressly understoocl that hf. scribed the texture of the ori compacted or rendered more ti'vely to the original texture whereby the dislr jis stifi'eneci, siren and rendered more suseeptihle or s. to sound vibrationsjw 1 The iiiaphre i; produced is pr with a central aperture attaches the sound-receiving or transmitting tie as indicated in dotted lines in Fi which the diaphragm is shown ap the sound box of e grephophone. disk after being treateci iri'the described is still lacking in the clesirecl s mass or is bulged in the center to o a met-s1 ring C is placed. on the ee i1 edge A of the disk and. subjected to a sew blows or to pressure so as to uniformly act on the periphery of the disk in manner to stifieu the latter or remove the bulge.

It is understood that the heating, pour 5- ing, pressing and hammering is clone the disk is held on a suitable anvil, indentations A. are also produced at time the dis is resting on such anvil or similar foundation. The disk may he list, as shown in Fig. 2; conical, as shown in Fig. 3; or spherical, as illustrstecl in Fig. 4, it being understoodthat for giving the desired form an anvil or form of conesponcling shape is used, on which the dish is pounded, beaten, pressed or hammered to give the disk the desired shape in ecliiition to rendering it exceedingly dense or corn pact. v

In practice I have found that for (lisphragn one and three-quarter inches in diameter use is made of sheet metal of or 29-gag;e, arui a disk out from this sheet 9 metal, or the sheet before the :fislcs are out, is reduced hy the pounding, beating, press ing, hammering or similar process to about 3-1: to 36rgege. 'For larger disks, two and a quarter inches in diameter, the sheet metal selected is of 24 to 26-gege the disk formed thereon is reduced by the process described to from 28 to 30-gege.

It is understood that the pounding e disk spree-(ls the same and thereby tensions the metal of the (lisk aml after operation is completed L iSl to the clesirel diameter.

A diephrs" descriherl sound-reproducing instrument or machine provides greatvolumes of sound or vibrati'ons of tones and sounds.

'Having thus described my invention, 1 claim as new and desire to secure by Letters Patent:

1. The iherein-clescribed method of making diaphragms for sound z'eproduoers, recorders, transmitters and receivers, which consists in cutting out a disk of sheet alumi num or similar metal and subjecting the disk to compression throughout to cause the metal to be compacted and flow from the center to the pei'iphery whereby the disk is tensioned by the radial flow of the meml, and whereby the disk of equal thickness tlncoughout.

2. The herein-described method of mak- FREDERIC W. THOMAS,

Wilmesses:

THEO. G. I*IOSLER; J12, PHELIP D. RQLLHAUS. 

